--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -5728,31 +5728,38 @@ nsLayoutUtils::AppUnitBoundsOfString(con
     totalMetrics += metrics;
     aLength -= len;
     aString += len;
   }
   return totalMetrics;
 }
 
 void
-nsLayoutUtils::DrawString(const nsIFrame*       aFrame,
-                          nsFontMetrics&        aFontMetrics,
-                          nsRenderingContext*   aContext,
-                          const char16_t*      aString,
-                          int32_t               aLength,
-                          nsPoint               aPoint,
-                          nsStyleContext*       aStyleContext)
+nsLayoutUtils::DrawString(const nsIFrame*     aFrame,
+                          nsFontMetrics&      aFontMetrics,
+                          nsRenderingContext* aContext,
+                          const char16_t*     aString,
+                          int32_t             aLength,
+                          nsPoint             aPoint,
+                          nsStyleContext*     aStyleContext,
+                          DrawStringFlags     aFlags)
 {
   nsresult rv = NS_ERROR_FAILURE;
 
   // If caller didn't pass a style context, use the frame's.
   if (!aStyleContext) {
     aStyleContext = aFrame->StyleContext();
   }
-  aFontMetrics.SetVertical(WritingMode(aStyleContext).IsVertical());
+
+  if (aFlags & DrawStringFlags::eForceHorizontal) {
+    aFontMetrics.SetVertical(false);
+  } else {
+    aFontMetrics.SetVertical(WritingMode(aStyleContext).IsVertical());
+  }
+
   aFontMetrics.SetTextOrientation(
     aStyleContext->StyleVisibility()->mTextOrientation);
 
   nsPresContext* presContext = aFrame->PresContext();
   if (presContext->BidiEnabled()) {
     nsBidiLevel level =
       nsBidiPresUtils::BidiLevelFromStyle(aStyleContext);
     rv = nsBidiPresUtils::RenderText(aString, aLength, level,

--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -112,16 +112,23 @@ struct DisplayPortMarginsPropertyData {
 } // namespace mozilla
 
 // For GetDisplayPort
 enum class RelativeTo {
   ScrollPort,
   ScrollFrame
 };
 
+// Flags to customize the behavior of nsLayoutUtils::DrawString.
+enum class DrawStringFlags {
+  eDefault         = 0x0,
+  eForceHorizontal = 0x1 // Forces the text to be drawn horizontally.
+};
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(DrawStringFlags)
+
 /**
  * nsLayoutUtils is a namespace class used for various helper
  * functions that are useful in multiple places in layout.  The goal
  * is not to define multiple copies of the same static helper.
  */
 class nsLayoutUtils
 {
   typedef mozilla::dom::DOMRectList DOMRectList;
@@ -1601,23 +1608,24 @@ public:
                                        DrawTarget* aDrawTarget,
                                        nscoord aWidth);
 
   static nsBoundingMetrics AppUnitBoundsOfString(const char16_t* aString,
                                                  uint32_t aLength,
                                                  nsFontMetrics& aFontMetrics,
                                                  DrawTarget* aDrawTarget);
 
-  static void DrawString(const nsIFrame*       aFrame,
-                         nsFontMetrics&        aFontMetrics,
-                         nsRenderingContext*   aContext,
-                         const char16_t*      aString,
-                         int32_t               aLength,
-                         nsPoint               aPoint,
-                         nsStyleContext*       aStyleContext = nullptr);
+  static void DrawString(const nsIFrame*     aFrame,
+                         nsFontMetrics&      aFontMetrics,
+                         nsRenderingContext* aContext,
+                         const char16_t*     aString,
+                         int32_t             aLength,
+                         nsPoint             aPoint,
+                         nsStyleContext*     aStyleContext = nullptr,
+                         DrawStringFlags     aFlags = DrawStringFlags::eDefault);
 
   /**
    * Supports only LTR or RTL. Bidi (mixed direction) is not supported.
    */
   static void DrawUniDirString(const char16_t* aString,
                                uint32_t aLength,
                                nsPoint aPoint,
                                nsFontMetrics& aFontMetrics,

--- a/layout/generic/nsPageFrame.cpp
+++ b/layout/generic/nsPageFrame.cpp
@@ -167,17 +167,17 @@ nsPageFrame::Reflow(nsPresContext*      
   PR_PL(("[%d,%d]\n", aReflowInput.AvailableWidth(), aReflowInput.AvailableHeight()));
 
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize);
 }
 
 nsIAtom*
 nsPageFrame::GetType() const
 {
-  return nsGkAtoms::pageFrame; 
+  return nsGkAtoms::pageFrame;
 }
 
 #ifdef DEBUG_FRAME_DUMP
 nsresult
 nsPageFrame::GetFrameName(nsAString& aResult) const
 {
   return MakeFrameName(NS_LITERAL_STRING("Page"), aResult);
 }
@@ -388,17 +388,19 @@ nsPageFrame::DrawHeaderFooter(nsRenderin
 
     // set up new clip and draw the text
     gfx->Save();
     gfx->Clip(NSRectToSnappedRect(aRect, PresContext()->AppUnitsPerDevPixel(),
                                   *drawTarget));
     gfx->SetColor(Color(0.f, 0.f, 0.f));
     nsLayoutUtils::DrawString(this, aFontMetrics, &aRenderingContext,
                               str.get(), str.Length(),
-                              nsPoint(x, y + aAscent));
+                              nsPoint(x, y + aAscent),
+                              nullptr,
+                              DrawStringFlags::eForceHorizontal);
     gfx->Restore();
   }
 }
 
 /**
  * Remove all leaf display items that are not for descendants of
  * aBuilder->GetReferenceFrame() from aList.
  * @param aPage the page we're constructing the display list for
@@ -730,17 +732,17 @@ nsPageBreakFrame::Reflow(nsPresContext* 
   // DidReflow will always get called before the next Reflow() call.
   mHaveReflowed = true;
   aStatus = NS_FRAME_COMPLETE; 
 }
 
 nsIAtom*
 nsPageBreakFrame::GetType() const
 {
-  return nsGkAtoms::pageBreakFrame; 
+  return nsGkAtoms::pageBreakFrame;
 }
 
 #ifdef DEBUG_FRAME_DUMP
 nsresult
 nsPageBreakFrame::GetFrameName(nsAString& aResult) const
 {
   return MakeFrameName(NS_LITERAL_STRING("PageBreak"), aResult);
 }